This invention relates to an information acquisition system and, more particularly, to an information acquisition system wherein response data in answer to a question which participants have been asked by a radio or television broadcast program is acquired at the broadcasting station.
Radio and television broadcasts include audience-participation shows in which public-opinion surveys, popularity polls, various questionnaires and the solicitation of quiz answers are carried out by telephone with the expectation of a high level of enthusiasm for participation by the audience. In order to realize audience-participation shows of this kind, an information acquisition system is required in which the response data from the audience is gathered and analyzed on the side of the broadcasting station.
FIG. 16 is a block diagram illustrating the construction of an information acquisition system according to the prior art. As shown in FIG. 16, the system includes participant telephones 1.sub.1, 1.sub.2, . . . , 1.sub.n, a telephone network 2, a terminating central telephone exchange 3 in the telephone network, and a broadcasting station 4 for television or the like. The broadcasting station 4 includes a private branch exchange (PBX) 5, which is the subscriber's terminating equipment, a data totalizing unit 6 for totalizing responses, and a broadcasting unit 7. Telephone lines 8.sub.1, 8.sub.2, . . . , 8.sub.n interconnect the terminating local telephone exchange 3 and the PBX 5. The solid lines L.sub.1, L.sub.2, . . . , L.sub.n represent line connections to the participants. These connections comprise physical circuits.
When participants are asked a question by an audience-participation show on television, for example, the participants use their own telephones to call the broadcasting station and answer "YES" or "NO", etc., to the question. The responses from the telephones 1.sub.1 .about.1.sub.n of the participants arrive at the terminating local telephone exchange 3 via the telephone network 2. These responses are then connected to the PBX 5 at the broadcasting station 4 through the plurality of lines 8.sub.1, 8.sub.2, . . . , 8.sub.n, and from the PBX 5 to the data totalizing unit 6. The data totalizing unit 6 totals and analyzes the responses from the participants. The results of analysis are broadcast via the broadcasting unit 7 so that participants can be informed of these results.
FIG. 17 is a block diagram showing a specific example of the arrangement of components within the broadcasting station in the conventional information acquisition system. Portions identical with those shown in FIG. 16 are designated by like reference numerals. As shown in FIG. 17, the PBX 5 includes a switch (SW) 5a, signal equipment 5b, a central processing unit (CPU) 5c, and a bus 5d. The data totalizing unit 6 includes data receiving circuits 6a.sub.1 .about.6a.sub.m, a central processing unit (CPU) 6b, a main memory (MM) 6c, a memory device 6d such as a hard disk for storing response data, and a bus 6e.
Each line from the terminating local telephone exchange 3 is connected to the switch 5a in the PBX 5 and to the signal equipment 5b, which sends and receives various signals. The switch 5a and the signal equipment 5b, which are connected to the CPU 5c via the bus 5d, perform line connecting and disconnecting processing and send and receive various signals under the control of the CPU 5c. For example, when a participant uses a telephone to call the broadcasting station, the call signal arrives at the terminating local telephone exchange 3 via the telephone network 2, and the terminating local telephone exchange 3 reverses the polarity of one idle line (assumed here to be line 8.sub.1). The signal equipment 5 senses the reversal in polarity and notifies the CPU 5c. The latter causes the signal equipment 5b to send an answer signal back to the terminating local telephone exchange 3 and controls the switch 5a to connect the line 8.sub.1 with a predetermined data receiving circuit that is capable of data reception. By virtue of the foregoing operation, a channel is formed between the telephone and the broadcasting station so that the response data is capable of being received from the telephone.
The lines from the participants that have been connected via the switch 5a are connected to respective ones of the data receiving circuits 6a.sub.1 .about.6a.sub.m, which proceed to receive the responses from the participants. The CPU 6b reads, via the bus 6e, the results of response reception in the data receiving circuits 6a.sub.1 .about.6a.sub.m and, by way of example, calculates the total number of responses, the total number "YES" responses and the total number of "NO" responses. The CPU 6b then stores the results of totalization in the memory device 6d. The results, stored in the memory device 6d, of totalizing the responses from the participants are broadcast appropriately via the broadcasting unit 7. It should be noted that programs necessary for operations such as the totalizing operation performed by the CPU 6b are stored in the main memory 6c.
FIG. 18 is a block diagram illustrating the construction of a data receiving circuit according to the prior art. The data receiving circuit includes a signal transceiver circuit 6a-1, an MF code-data analyzing circuit 6a-2 for receiving and analyzing response data comprising a multi-frequency code, a microprocessor (.mu.P) 6a-3, a main memory (MM) 6a-4, and a bus 6a-5. The MF code-data analyzing circuit 6a-2 analyzes a participant's response, which is in the form of an MF code of a push-button telephone or the like sent via an analog line. More specifically, if a participant's response to a question is "YES", the participant uses his telephone to enter "#0*". If the participant's response is "NO" then the participant presses the keys for "#1*". It should be noted that the symbols "#", "*" are for demarcation purposes, wherein "#" indicates the start of a numeral and "*" the end of a numeral. The numerals "0", "1" indicate "YES" and "NO", respectively. Since the telephone network 2 is adapted so as to sequentially transmit the frequency codes corresponding to the keys pressed, the MF code-data analyzing circuit 6a-2 analyzes the received multi-frequency code data and determines whether a response is "YES" or "NO". The results of analysis are stored in the form of a digital signal in the main memory 6a-4 via the bus 6a-5. The stored information is read into the CPU 6b via the bus 6e, and the CPU 6b totalizes the information and sends the totalized results to the broadcasting unit 7. Though the signal transceiver circuit 6a-1 is not always required, it is adapted to receive signals other than the response data sent from the line side, and to transmit predetermined signals, in a case where highly sophisticated response-data acquisition is carried out. The microprocessor 6a-3 controls the operation of the signal transceiver circuit 6a-1, MF code-data analyzing circuit 6a-2 and main memory 6a-4 via the bus 6a-5.
In an analog telephone network, the number of telephone lines that can be installed between the broadcasting station 4 and the terminating local telephone exchange 3 is physically limited. For example, several score to a hundred of such lines may be provided. Consequently, in the conventional information acquisition system, undesirable phenomena occur, such as lines being found busy, when a large number of participants take part in the program. Though it is believed that several thousand to several tens of thousands of participants are needed in order to have a successful audience-participation show, the state of the art in conventional information acquisition systems is such that the aforementioned phenomena, e.g., busy lines, occur owing to the physical limitation upon the number of lines. Thus, a practical problem which arises is that, in actuality, there is a limit upon the number of participants that are capable of taking part in audience-participation shows.
Further, in cases where participation in a radio or television program is allowed freely throughout the country, a terminating congestion can occur on a nationwide scale in the local telephone exchange which accommodates the broadcasting station, and this can put considerable pressure on the normal connecting function of the telephone network. As a consequence, it is necessary to place a limit upon the regions from which participants can take part or to limit telephone numbers, such as by limiting telephone numbers to those whose last digit is 0. Thus, a problem which arises is that all members of the audience wishing to participate cannot do so freely.